Bottom hole control choke



y 9 H; U. GARRETT 2,156,429

BOTTOM HOLE CONTROL CHOKE Filed April 26, 1957 2 Sheets-Sheet l I Ff-'36 l8 3 37-- X34 35 L O /6 9 I r INVENTOR.

Henry U Gar/e7? HG.

ATTORNEY.

- Patented May 2, 1939 UNITED STATES 2,156,429 BOTTOM HOLE CONTROL CHOKE Henry Udell Garrett, Tyler, Tex., assignor to The Guiberson Corporation, Dallas, Tex., a corporation oi Delaware Application April 26, 1931, Serial No. 138,926

11 Claims.

In producingoil wells there is frequently a gas stratum above the sand containing the oil, which gas stratum may be under. very high pressure. I propose to utilize this pressure by puncturing the casing and providing a valve communicating with the flow line, which valve is operated by the gas pressure admitted into the casing through the said holes. to place packers above and below the perforations made in the casing, thereby forming a pressure chamber between the said packers, into which chamber the gas from the stratum passes through the said holes and thence through the said valve into the flow line. Another object of the invention is to provide a control means on the surface of the ground whereby the pressure above the uppermost packer may be regulated. In practice I find it ad visable to form a by-pass around the said valve sothat the trapped gas in the said chamber will pass into the casing above the upper packer. The regulator on the surface of the ground affords a means of regulating the pressure in the casing above the upper packer so that there will be a differential in pressure in the casing above the upper packer from the pressure existing in the chamber between the said packers. I consider it an important object of the invention to bleed off or diminish the pressure above the upper packer so as to control the 'said valve. Heretofore it has 'been the custom to introduce gas under pressure from the surface so that it will unseat a valve and permit the gas pumped in to pass into the flow line. I reverse this operation by utilizing the gasin the said stratum instead of pumping air or other gases into the casing, and in the construction shown in this application I partially exhaust the gases to atmospheric pressure in the casing above the upper packer instead of introduc'ing gas therein from a pump or other means.

I also provide a gate valve whereby the exhaustion of gas above the upper packer may be stopped so that the pressure above and below the upper packer will be equalized. In this case a spring will seat the valve and prevent the introduction of gas into the flow line.

The lower packer may be omitted in case it is desired to utilize the gas in the oil, and in this case the perforations ,inithe casing would not be required. The Oiland gas would now unseat the valve so that bothuthe oil and the gas therein would flow throughthe valve passage.

These and other objects of the invention will appear in the detailed specification and claims which follow. In the drawings, Fig. l-illustrates In practice I find it advisable a. portion'of the casing, the upper packer, and a portion of the flow line, certain of the parts being shown in cross-section. Fig. 2 is a similar -view of thelower packer and associated parts,

it being understood that the parts shown in Fig. 1 5 are above the parts shown in Fig. 2. Fig. 3 is a cross-sectional plan view on the line 3-3 of Fig. 1. Fig. 4 is a side elevational view of. the control mechanism above the ground.

In the drawings, l represents the casing, which 1 terminates in a casing head 2 above the ground.

' The casing head 2 is provided with a. convenwell. Extending laterally from the casing head 2 is a pipe 5 to which is attached a gate valve 6. Extending from the gate valve 6 is a pipe 1, extending to a regulator 8, which may be of any conventional type, which may be set to regulate 20 the pressure in the casing, for the said regulator communicates with the chamber between the casing I and the flow line 4. All'of the parts above mentioned, with the exception of the casing 'and the flow line, are above the ground, and it 25 is of course understood that the casing and the flow line extend downwardly throughthe well. If there is a known stratum containing high pressure gas, the casing I should be punctured in a well known manner, forming a plurality of holes 9 adjacent to the said stratum, so that the gas in the said stratum can pass through the holes 9 into the casing I. Below the said holes I position a packer, hereinafter referred to as the lower packer ID. The structure of the lower 35 packer is shown in Fig. 2 and need not be described in detail, for it is conventional. It might be briefly stated, however, that that there is a valve ll secured to the flow line which, when the packer is being loweredin the well, is above its '40 valve seat l2, and the hook l3 receives the pin ll, holding the slips 15 in their lowermost position. Whenthe lower packer has reached the point where it is desired to set the same, the flow line 4' is rotated so as to remove the pin I4 45 from the hook l3, and when the flow line is then lowered slightly, the springs l6 engage the inner side walls of the casing, thereby holding the collar ll against downward movement, and the links l8 move the slips l5 upwardly on the cone l9 so 5 that they engage and grip the'inner walls of the casing. As the flow' line moves further downwardly, the valve Il moves against its valve seat I! and compresses the resilient packer l0 against the collar 20. carried by the cone l9, thereby packing off the part of the casing above the packer from that below the same.

When the lower packer is set,/the flow line a between the lower packer and the upper packer 23, now to be described, is held against further downward movement so that the collar 25, carried by the lowermost part of the upper part of the flow line 6, moves' against the collar 22 compressing the said'packer into engagement with the inner side walls of the casing. The upper packer 23 is positioned above the perforations 9 so that there is a gas chamber 25 formed between the said packers and communicating, through the holes 9, with the gas in the stratum. The collar 24 is screw threaded, as shown in Fig. l, to a collar 26, which is screw threaded on the section of the flow line between the said packers. A guide 2'! is secured to the collar 2| so as to relieve the upper packer from undue friction by properly centering the same while it is being introduced in the casing.

A chamber 28 is formed between the flow line l and the casing above the upper packer. Since the chamber 25 is directly exposed to the gas in the stratum, it might properly be called a pressure chamber, and since the chamber 28 extends upwardly through the casing and outside of the flow line 8 and communicates with the-regulator 8, the said chamber 28 might be considered as a control chamber.

A small pipe 29, forming a by-pass, extends from the control chamber 28 downwardly through the collar 22, the packer 23, the collar 24, and into the collar 26, and communicates with a channel 30, extending through the said collar. A valve 3| is positioned in the said channel 30, and is somewhat smaller than said channel so that gas may flow around said valve. Between the lowermost portion of the said pipe 29 and above the said valve 3| is a spring 32, tending to push the said valve downwardly and to seat the conical valve stem 33 on the valve seat 34. The valve seat 3 5 is formed on the upper end of an L-shaped passage 35, extending from a passage way 36, extending from the pressure chamber 25, and the said passage 35 communicates with the interior of the flow line or with the bore 31 in the collar 36, which forms a part of the flow line.

The oil normally flows from the bottom of the well upwardly through the flow line 8 to some point above the upper packer. Let us assume that the pressurein the oil well is not suflicient to cause the oil to flow to the surface, but that a gas stratum is found which contains a pressure of 2: pounds. This pressure which passes through the holes 9 passes upwardly around the sides of the valve 3|, through the channel 30v and pipe 29, into the control chamber 28, and if the gate valve 6 were closed it would only be a matter of time until the pressure in the chambers 25 and 28 would be equalized, and the spring 32 would close. If, however, the gate valve is opened and the regulator is set to a pressure sufliciently below a: poundsto enable the pressure in the chamber 25 to unseat the valve 3| against the tension of the spring 32, the gas from the pressure chamber 25 would flow through the channel 35 into the flow line, thereby aerating the oil in the flow line and causing the oil to flow to the surface. The amount that the valve will" be opened would be altogether dependent upon the difierential in pressure between the chambers 28 and 25. The pressure in the chamber 28 can never exceed that in the chamber 25, for the only pressure in the chamber 28 is the pressure .that

has been caused by thepassage of gas from the chamber 25 into the chamber 28. It the pressure should be equal, the spring 32 will of course close the valve altogether. Ifthe pressure in chamber 25 should be only very slightly greater than that in chamber 28, the valve would be un- "seated very little, so that a very small quantity Particular attention is called to the fact that I regulate the valve 3| not by introducing pressure into the chamber 28 from a pump, but by allowing the gas therein to be partially evacuated, and the amount of this evacuation is con.- trolled by the regulator 8.

If there is a considerable gas'pressure in'the oil and it is desired to use the bottom hole pressures, the holes 9 may be eliminated, and the lower packer may be omitted. It would. then be necessary to plug the bottom of the flow line 4 so as to force the oil and gas to pass, upwardly through the pressure chamber 25, unseating the valve, and both the oil and the gas would then pass through the channel 35, into the flow line.

t by setting the regulator 8 to any point desired.

I, therefore, have provided a proficient bottom hole control choke,'which is controlled entirely from the surface of the ground. In using the Words bottom hole control choke I do not, of course, mean to define the exact position of the packersrelative to the bottom, for obviously the packers could be positioned wherever a gas stratum is found, provided the oil will flow to a point above the said packers so thatwhen the gas is introduced, it will aerate the oil.

I realize that many changes may be made in the specific form in the invention, shown by way of illustration herein, and I desire to reserve to myself the right to make all changes which may fairly fall within the spirit of this invention as expressed in the appended claims. Having now described my invention, I claim:

1. In combination, a casing perforated adjacent a gas stratum, a flow line, an upper packer and a lower packer carried by said flow line, means whereby said lower packer may be set below the perforations and the'upper packer above the said perforations, forming a pressure chamber between said packers, and manually controlled means to govern the introduction 9f the trapped gas in the pressure chamber into the oil in the flow line.

2. In combination, a casing perforated adjacent a gas stratum, a flow line, an upper packer and a lower packer carried by said flow line, means whereby said lower packer may be set below the perforations and the upper packer above the said perforations; forming a pressure chamber between said packers, and means controlled from the surface of the ground to govern the introduction of the gas in the pressure chamber into the oil in the flow line.

3. In combination, a casing perforated adjaand a lower packer carried by said flow line,

means whereby said lower packer may be set below the perforations and the upper packer the differential in pressure in the said chambers will control the introduction of gas from the pressure chamber into the flow line.

4. In combination, a casing, a flow line, a packer carried by the flow line, a regulator to regulate the pressure of gas in a control chamber between the flow line and casing and above the packer, the space below the packer and the flow'line and casing forming a pressure chamber, there being a passage way between the pressure chamber extending into the flow line and a valve to control the opening to said passage, said valve being controlled by the differential in pressure in said chambers to regulate the amount of gas that may pass through said passage way.

5. In combination, a packer, a flow line carrying said packer, a casing through which said flow line extends, the space between the flow line and casing above the packer forming a control chamber and the space below the packer forming a pressure chamber, there being a passage way from said pressure chamber.into said flow line, and means, governed by the differential in pressure in said chambers, to govern the amount of gas that may pass through said passage way.

6. In combination, a packer, a flow line carrying said packer, a casing through which said flow line extends, the space between the flow line and casing above the packer forming a control chamber and the space below the packer forming a pressure chamber, the pressure chamber being in communication with the gas in a stratum in the well, there being apassage way from said pressure chamber into said flow line, and means, governed bythe differential in pressure in said chambers, to govern the amount of gas that may pass through said passage way.

7. In combination, a flow line, a packer thereon having a control chamber above and a pressure chamber below the same, the packer having a by-pass extending therethrough and communicating with the said chambers so that the pressure in the chambers will at all times tend to .be equalized, adjustable means to control the pressure in the control chamber, and a valve means to govern the introduction of gas from the pressure chamber into the flow line.

sure in the chambers 8. In combination, a fiow line, a packer thereon having a control chamber above and a pressure chamber below the same, the packer having a by-pass extending therethrough and communicating with'the said chambers so that the pressure in the chambers will at all times tend to be equalized, adjustable means to control the pressure in ,the control chamber, there being a passage way extending from the pressure chamber into the flow line, and a valve means to control the amount of gas that may pass through said passage way.

9. In combination, a flow line, a packer thereon having a control chamber above and a pressure chamber below the same, the packer having a by-pass extending therethrough and communicating with the said chambers so that the pressure in the chambers will at all times tend to be equalized, adjustable means to control the pressure in the control chamber, there being a passage way extending from the pressure chamber into the fiow'line, a valve normally tending to closesaid passage way and being controlled by the differential .in pressure in said chambers.

10. In combination, a flow line, a packer thereon having a control chamber above and a pressure chamber below the same, the packer having a by-pass extending therethrough and communicating with the said chambers so that the pressure in the chambers will at all times tend to be equalized, adjustable means to control the pressure in the control chamber, there being a passage way extending from the pressure cham ber into the flow line, a valve having its opposite ends exposed to the pressure in said chambers respectively, so that it is controlled by-the differential in pressure in said chambers.

11. In combination, a flow line, a packer thereon having a control chamber above and a pressure chamber below the same, the packer having a by-pass extending therethrobgh and communi eating with the said chambers so that the preswill at all times tend to, be equalized, adjustable means to control the pressure in the control chamber, there being a passageway extending from the pressure chamber into the flow line, a spring pressed valve having its opposite ends sure in said chambers respectively, so that it is controlled by the difierential' in pressure in said chambers.

HENRY UDELL GARRETT.

exposed to the pres-- 

